Semiconductor light emitting element and method for manufacturing same

Abstract

According to one embodiment, a semiconductor light emitting element includes a first semiconductor layer, a second semiconductor layer, and a light emitting unit. The first semiconductor layer includes an n-type impurity having a first concentration. The second semiconductor layer includes a p-type impurity. The light emitting unit is provided between the first and second semiconductor layers. The light emitting unit includes a first barrier layer, a second barrier layer provided between the first barrier layer and the second semiconductor layer, a third barrier layer provided between the second barrier layer and the second semiconductor layer, a first well layer provided between the first and second barrier layers, and a second well layer provided between the second and third barrier layers. A plane including a boundary between the first barrier layer and the first well layer intersects a plane including a (0001) plane of the first semiconductor layer.

What is claimed is: 
     
         1 . A semiconductor light emitting element, comprising:
 a first semiconductor layer including an n-type impurity having a first concentration;   a second semiconductor layer including a p-type impurity; and   a light emitting unit provided between the first semiconductor layer and the second semiconductor layer, the light emitting unit including
 a first barrier layer, 
 a second barrier layer provided between the first barrier layer and the second semiconductor layer, the second barrier layer including an n-type impurity having a second concentration higher than the first concentration, 
 a third barrier layer provided between the second barrier layer and the second semiconductor layer, 
 a first well layer provided between the first barrier layer and the second barrier layer, and 
 a second well layer provided between the second barrier layer and the third barrier layer, 
   a plane including a boundary between the first barrier layer and the first well layer intersecting a plane including a (0001) plane of the first semiconductor layer.   
     
     
         2 . The element according to  claim 1 , wherein an angle between the boundary and the (0001) plane is not less than 15 degrees and not more than 165 degrees. 
     
     
         3 . The element according to  claim 1 , wherein the boundary is tilted with respect to the (0001) plane. 
     
     
         4 . The element according to  claim 1 , wherein the second concentration is not less than 2.0×10 18  per cubic centimeter. 
     
     
         5 . The element according to  claim 1 , wherein the second concentration is not less than 5.0×10 18  per cubic centimeter. 
     
     
         6 . The element according to  claim 1 , wherein a thickness of the second barrier layer is not less than 3.0 nanometers and not more than 7.0 nanometers. 
     
     
         7 . The element according to  claim 1 , wherein the first barrier layer and the third barrier layer have thicknesses not less than 3.0 nanometers and not more than 7.0 nanometers. 
     
     
         8 . The element according to  claim 1 , wherein the first well layer and the second well layer have thicknesses not less than 3.5 nanometers and not more than 7.5 nanometers. 
     
     
         9 . A method for manufacturing a semiconductor light emitting element, comprising:
 forming a first semiconductor layer on a substrate, the first semiconductor layer including an n-type impurity having a first concentration;   forming a light emitting unit on the first semiconductor layer, the light emitting unit including a first barrier layer, a second barrier layer provided on the first barrier layer, a third barrier layer provided on the second barrier layer, a first well layer provided between the first barrier layer and the second barrier layer, and a second well layer provided between the second barrier layer and the third barrier layer, the second barrier layer including an n-type impurity having a second concentration higher than the first concentration; and   forming a second semiconductor layer on the light emitting unit, the second semiconductor layer including a p-type impurity,   a plane including a boundary between the first barrier layer and the first well layer intersecting a plane including a (0001) plane of the first semiconductor layer.   
     
     
         10 . The method according to  claim 9 , wherein an angle between the boundary and the (0001) plane is not less than 15 degrees and not more than 165 degrees. 
     
     
         11 . The method according to  claim 9 , wherein the boundary is tilted with respect to the (0001) plane. 
     
     
         12 . The method according to  claim 9 , wherein the second concentration is not less than 2.0×10 18  per cubic centimeter. 
     
     
         13 . The method according to  claim 9 , wherein the second concentration is not less than 5.0×10 18  per cubic centimeter. 
     
     
         14 . The method according to  claim 9 , wherein a thickness of the second barrier layer is not less than 3.0 nanometers and not more than 7.0 nanometers. 
     
     
         15 . The method according to  claim 9 , wherein the first barrier layer and the third barrier layer have thicknesses not less than 3.0 nanometers and not more than 7.0 nanometers. 
     
     
         16 . The method according to  claim 9 , wherein the first well layer and the second well layer have thicknesses not less than 3.5 nanometers and not more than 7.5 nanometers.